Wire cloth selvage



June 2, 1931. L. c. CAMPBELL 1,808,526 I WIRE CLOTH SELVAGE Filed Sept.21'. 1929 1 IWFJW ii INVENTOR Lqggtil Campbell A'IT RNEY Patented June 21931 UNITED STATES PATENT OFFICE LEGGET'I G. CAMPBELL, 0F NEWARK, NEWJERSEY, ASSIGNOR TO NEWARK WIRE CLOTH COMPANY, OF NEWARK, NEW JERSEY, ACORPORATION OF NEW JERSEY WIRE CLOTH SELVAGE Application filed September21, 1929. Serial No. 394,324.

This invention relates to metallic wire cloth selvages and isparticularly applicable to wire cloth for use in screen grids for radiotubes. Such grids are made of camparatively narrow cloth. To makeselvages on the edges of such narrow cloth by weaving methods increasesthe cost thereof unnecessarily. Furthermore, it is quite difficult andexpensive to use present machines for the weaving of cloth of suchnarrow widths with woven selvages thereon. Some means, however, shouldbe used for preventing the cloth from unraveling.

My invention contemplates the production of such an edge on the cloth asforms a satisfactory and efficient selvage preventing the cloth fromunraveling without the necessity for weaving or otherwise manipulatingthe wires of the cloth, and such as can be inexpensively madesimultaneously with the cutting of the cloth to the desired width. Thevarious objects of my invention will be clear from the description whichfollows, and from the drawings, in which r Fig. 1 is an elevational viewon a greatly enlarged scale of a piece of metallic wire cloth showing myimproved selvage thereon.

Fig. 2 is a sectional view of the same, and

Fig. 3 is a view similar to Fig. 1, of the partly severed and selva-gedcloth.

In that practical embodiment of my invention which I have illustrated byway of example, the cloth may consist of iwarp wires 10 and weft wires11, said wires being interwoven in the customarymanner as is well knownin the art, to provide a cloth opening 12, shown as slightly greaterthan the diameter of the wires.

It will be understood that the dimensions my inventionmay be applied tocloths of many different dimensions. At the edge of the piece of cloth,I provide my improved selvage indicated generally by the numeral 13which when viewed by the naked eye, presents the appearance of acompletely closed or sealed edge. Said selvage is quickly, easily andinexpensively formed automatically when the cloth is severed to thedesired width by my improved method, as is fully pointed out in mycopending application for patent for machine for and method of makingselvages for wire cloth, Serial No. 394,325, filed September 21st, 1929.

As indicated in Fig. 3, the cloth may be woven in any width which may befound convenient and economical in the operation of the cloth weavingmachines. In order, however, to provide a comparatively narrow strip ofsuch cloth, of uniform width throughout, such as for instance, is of theproper width for use in radio tube screen grids, the cloth is severed bymeans of a suitable tool which severs the weft wires 11 andsimultaneously bends and points said wires to form the selvage 13. Thetool 14 which I prefer to use for this purpose is indicateddiagrammatically in Fig. 3. The thickness' of the tool, however, isshown on a greatly exaggerated scale in order to indicate the severingoperation with greater clarity. Said tool being fully Sufiice it to saythat in order to cut the,

cloth and to simultaneously form'the selvage thereon, the tool is pushedbetween adjacent warp wires 10 and moved through the cloth, or the clothis pulled against the tool, the edge of which remains at all times abouthalf way between a pair of'the warp wires.

After the cutting and bending operation has been completed, it will beseen that the ends 15a and 15b of adjacent weft wires 11 liesubstantially on opposite sides of the edge warp wire 16. For example,the bent ends 15a of alternate weft wires, as illustratedin Figs. 2 and3, are arranged substantially nearer the rear face ofthe cloth, whilethe 1 ends 15?) of the other weft wires are nearer the front face of thecloth. Furthermore, the edge warp wire 16 is arranged nearer itsadjacent warp wire 17 than the normal distance between the warp wires,that is, a distance less than the cloth opening 12. The edge warp wire,by reason of this arrangement, usually produces an edge-cloth opening 20of about half the width of the normal cloth opening 12.

In the finished selvage, the end portions 15a and 15b of the weftwires'lO may be of slightly greater length than one-and-onehalf timesthe normal distance between adjacent warp wires for the reasonthatsaid-"end portions may be slightly stretched during the cuttingoperation. It will be seen,- therefore, that said ends projectbeyond'the edge warp wire 16 a distance less than the. normal distancebetween warp wires 10. 'Saidends 15a and 15b, furthermore, duet-othecutting operation, terminate in more or less'flatsurfaces such as18, substantiallyparallelto the axes of the warp wires 10," 16 and l'fand thereby forming a point as 19 oneac'h of the ably turned through anangle of approximately 90 so that the point 19 of:-one"bent end 15a liesquite closeto and may possibly, though not usually, touch the bent end15?) of the nearest succeeding parallel weft wire.

However, even though the point does not so touch the next bend, it liesso close to said bend that the edge of the-cloth. at'tlre selvageappears substantially closed or sealed. This appearance .andstructureisaided by the 'fact that the bent portions 15a and15b; lie closer toeach other than do the weft or warp wires,

owing to the formation of said'bends. V

Whilethe bent portions 15a and'15-bl may extend through an angle.slightly less than 90"., or equal thereto, or slightly greater than 90.said bend usually 'extendsfthrough an angle in all cases less than180?,thebends being all of substantially the same curvature, and allbeing single bends as distinguished from ;.double bends, or bends alongreverse curves. Said bends may begin at the'warp wire 17 or slightlythereabove, depending largely on the manner in whichthe tool cuts theweft wires. 7 In other words, the bent end portions 15a and.15b are allof substantially the same curvature and all point substantially in thesame direction, all being bent away'from the axis of the correspondingweft wire toward the next succeeding weft wire.

It will be seen that the edge warp wire 16 cannot move outwardly towardthe edge of the cloth since it is prevented from doing so bythe .bends15a and 15b and cannot pass through the practically closed spacetherebetween, nor can said edge warp wire move towards itsadjacentwire17 owing to the interweaving thereof in'the usual manner 7 with theweft wires. It will also be seen that for the same reason, the weftwires 11 cannot move relatively even though the ends thereof arefree andindependent of each other so that unraveling of the cloth is preventedby my improved selvage.

, Itwill be seenthat I have provided a simple, inexpensive and eflicientselvagefor narrow widths of wire ;cloth, Well adapted use.

It will be understood that while *I have shown and {described apreferred :embodiment of my invention, I'do'not-Wish to be understood aslimiting myself thereto butirP intend to claim my invention 1 as broadly;-as maybe permitted bythe state-of the prior art and the terms of theappended claims.

'. "I claim: 1

In a Wire fabric comprising interwoven: warp wires andwe'ft wires, aselvage comto meet the severe requirements of practical- 85 prising anunmutilated edge warp wire.

spaced. from the adjacent warp wire "dist-ancef less than i the normaldistance between said warp wires, and terminal bent GI1'Cl 'OI1i'51 eachweft wire "extending slightlyabove said edge warp wire and bent'throu-ghan angle of: approximately '90 toward the adjacent weft wire andpointed, said'bent ends 'havingfa' single curvature only and allcx-L-itending in-thesame direction. f

'QJ-In a woven wire fabric having a set of interwoven warp wiressubstantially parallel to each other anda-set of weft wiressubstantially parallel to each other and Elf-(r4 -ranged atsubstantially right' angles=tothe warp wires, a selvage'including'anendon each are parallel set of wires bent substan- "tiallyin the-plane'of the face of'saidcloth, and out ofthe-line of'the axis of the wireiI1' airl (curve directed towards the next succeedinv parallel-Wire',-said end being pointed and substantially free of the adjacentparallel 1 In a woven wire'=fabric including=a set -of "substantiallyparallel wires, a selvage formed by bending the ends of said wires inthe same direction substantially in the plane of the faceof' the cloth,each'bent 'end terminating in {advance of and being free of thenextsucceeding parallel wire but-sufficiently close thereto; to form asubstantially closed edge on the cloth.

4. In a woven wire fabric including a set a of --'substantially parallel:wires, 5 a 'bent end on each of said wires forming a selvage for saidfabric, said end being curved toward the next adjacent parallel wirealong aline of single curvature but being self-maintained free andindependent of said adjacent wire and terminating at a point in advanceof said adjacent wire and of the curved end thereof.

5. In a woven wire fabric including a set of substantially parallelwires, a bent end portion on each of said wires curved through an anglenot greater than 90 toward the next succeeding parallel wire, said endportion terminating in a substantially flat surface arrangedsubstantially at right angles to the axis of the remainder of said wireto form a point on said end.

6. In a woven wire fabric having a substantially parallel set of warpwires and another parallel set of weft wires arranged substantially atright angles to the warp wires, a selvage comprising an edge warp wirespaced from its adjacent warp wire a distance less than the distancebetween the remaining warp wires, and substantially independent bentends on said weft wire maintaining said edge warp wire and said weftwires in place against unraveling.

7 In a woven wire cloth fabric, a selvage comprising an edge warp wirespaced from its adjacent warp wire a distance less than the clothopening, weft wires extending past said edge warp wire, and endson saidweft wires all bent in the same direction and substantially free andindependent of each other for maintaining said edge warp wires and saidweft wires in place, the alternate ends of said weft wires beingarranged on one side of said edge warp wire corresponding to one face ofthe cloth and the other alternate ends being arranged on the other sideof said edge warp wire corresponding to the other face of the cloth.

8. In a woven wire fabric, an edge warp wire and weft wires projectingbeyond said warp wire a distance less than the cloth opening, the end ofeach of said weft wires beginning at the second warp wire from the edgeof the fabric, being bent toward the bent end of the next succeedingweft wire.

9. In a woven wire cloth fabric, a set of substantially parallel wiresand ends on said wires of less length than twice the cloth opening, eachof said ends having a single bend terminating close to the bent end ofthe succeeding parallel wire and extending through an angle of less than180 to form a substantially closed selvage.

10. A selvage for a woven wire fabric comprising an edge warp wirespaced from its adjacent warp wire a distance less than the normal clothopenings, and bent portions on the ends of the weft wires, the bends ofsaid bent portions beginning at a point below said warp wire andsubtending an angle of approximately 90 and each terminating in advanceof the succeeding bent portion.

11. A selvage for a woven wire cloth fabric comprising an edge warp wirespaced from its adjacent warp wire a distance less than the remainingcloth openings, and ends on the weft wires bent substantially in theplane of the face of the cloth and all extending in the same directionbut self-maintained out of engagement with each other.

12. A selvage for a woven wire cloth fabric comprising an edge warp wireparallel to the remaining warp wires but spaced therefrom a distanceless than the normal spacing between warp wires, a bent end on each weftwire, said ends being substantially parallel to each other and each ofsaid ends terminating beyond the edge warp wire in advance of thesucceeding bend toward which it is directed.

13. A selvage for a woven wire cloth fabric comprising an edge warp wirespaced from its adjacent warp wire a distance less than the clothopening, and free ends on the weft wires all bent in the same directionand extending beyond said edge warp wire toward the edge of the clothand terminating at the extreme edge of the cloth substantially to closesaid edge.

14. A selvage for a woven wire cloth fabric comprising a series ofsubstantially parallel wires and free end portions on said wires eachbent along a line of single curvature substantially in the plane of theface of the cloth through an angle of approximately 90 and terminatingat the extreme edge of the cloth to form said edge.

15. A selvage for a woven wire cloth fabric comprising a series ofsubstantially parallel wires, an edge wire arranged at right angles tosaid parallel wires, and spaced bent ends on said parallel wires, theadjacent ones of said ends lying on opposite sides of said edge wire,said ends being of similar shape and each curved along a line of singlecurvature and terminating beyond said edge wire and at the extreme edgeof the cloth and substantially closing the edge of the cloth.

16. A selvage for a woven wire cloth fabric comprising pointed and bentend portions of a set of parallel wires, said end portions all extendingin the same direction and terminating at the extreme edge of the cloth,and said end portions being substantially parallel and spaced apartthrough the greater portion of their length a distance less than thenormal cloth opening for substantially closing the edge of the cloth.

LEGGETT C. CAMPBELL.

